[openib-general] mthca calls ib_register_mad_agent() and implements ib_device.process_mad()?

[Roland Dreier]

    Ralph> Can someone explain why the mthca driver calls
    Ralph> ib_register_mad_agent() and implements
    Ralph> ib_device.process_mad()?  It looks like the later does the
    Ralph> actual processing of MAD packets for the SMA and PMA
    Ralph> whereas the former doesn't seem to do anything except cause
    Ralph> the ib_mad module to be modprobe'd.

The MAD agent is created to handle sending MADs that the device itself
generates -- traps and notices essentially.  Look at
mthca_mad.c::forward_trap() to see where it gets used.

MADs from the network are passed down to the firmware in the
process_mad method, and those replies are returned back up the the MAD
layer for sending.

 - R.